Still, how to tell if an employee is being worked too hard is a legitimate question. In our experience, depending on the employee, it is possible to demand more and more until the workload becomes unreasonable. Yet, employers can fall into the trap of overworking their best employees. After all, we all want our top talent to take on more assignments, right? And, we want them to do the best work they can.

Depending on an employee’s behavioral type, then -- as well as the requirements of the job and the individual's family situation, age and health status -- how much work he or she can and should tackle on a weekly basis will vary.

Since people don’t come in a one-size-fits-all package, how do we discern that we are putting too much pressure or workload on an employee? We suggest looking at the following warning signs:

People are working nights, early mornings and weekends.

Pay attention to when your employees arrive at and leave from work. Sometimes, security systems can provide this information. If you see an increase in hours, it may be time to examine your employees’ workload.

Remember, there is a difference between a marathon and a sprint. If you have a cyclical business that occasionally requires employees to work additional hours (e.g. accountants during tax season), this will be acceptable. However, if there is no end in sight to the long hours, you may need to re-examine work assignments or staffing.

People are missing family commitments for the job.

If you hear that employees are missing family obligations because they feel they cannot take time from their jobs, you're likely looking at an indicator that employees feel overworked. We know a former employee of a blue chip consulting firm who chose a different path when his demanding job kept him from attending his children’s activities.

He told us about sitting in his hotel room in Manhattan, “crying like a baby” because he was missing his son’s first t-ball game. Within a year, he had moved to a position with another firm that required less travel and gave him more flexibility and control over his schedule.

People seem more emotional.

When people feel overworked, the result can be sleep disruption and, as noted above, increasing difficulties with family members. More drama in the workplace may occur.

In particular: If formerly rational employees seem more on the edge, you may want to look at workload as a possible cause. Similarly, people who have a high need to please may overcommit due to a fear of rejection or a fear of failure. People pleasers can become extremely resentful, passive-aggressive and sometimes actively aggressive if they feel that their hard work is undervalued.

One way to combat this pattern is to make sure that you show your employees appreciation for the value they bring to the organization.

Quality decreases.

As the Harvard Business Review wrote, studies seem to agree that overwork causes diminishing returns. As employees work longer, they “progressively work more stupidly on tasks that are increasingly meaningless.” There is a reason why factory-owners in the 19th century began to limit workdays, first to 10, and then eight, hours. They found that as they did, output increased and expensive mistakes and accidents decreased.

More recent experiments have confirmed these results. People who take the required time off are more productive. If you see mistakes increasing at your worklace, look at employee workload and hours worked as the possible cause.

Voluntary turnover increases.

If you are experiencing higher levels of voluntary turnover (especially with key talent), you may want to examine work levels. Talented employees who are motivated and ambitious are normally eager to take on additional or time-consuming assignments. However, if those same assignments cause issues with their meeting their family obligations -- or they don't receive promotions or raises, or they feel undervalued -- those same employees may decide to move on.

When this happens, it is too late. To avoid losing talented employees, keep an eye out for the above signs and keep workloads at reasonable levels.

While employees are adults who should make their own decisions, employers need to be cognizant of the demands they place on their workers. Employees who work hard to please others, are overly focused on getting ahead or are especially ambitious can be particularly vulnerable to taking on too much.